Exception Handling / Error Handler in C++
What is Exception Handling in C++?
Explanation
Exception Handling provides a mechanism to detect and report an exceptional circumstance, so that corrective action can be taken to set right the error occurred. Error Handler in C++ consists of three major keywords namely
try,
throw and
catch. The
"try" block is a set of code which generates an exception which is thrown using the
"throw" statement. The
"catch" block is used to catch the exception and handles it appropriately.
Throw point |
Function that causes an exception. |
try block |
Invokes a function that contains an exception. |
catch block |
Catches and handles the exception. |
Example :
#include <iostream.h> int main() { int x,y; cout << "Enter values of x::"; cin >> x; cout << "Enter values of y::"; cin >> y; int r=x-y; try { if ( r!=0) { cout << "Result of division is x/r:: " << x/r << "\n"; } else { throw ( r); } } catch( int r) { cout << "Division by zero exception:: value of r is::" << r << "\n"; } cout << "END"; return 0; } |
Result :
Enter values of x::12
Enter values of y::12
Division by zero exception::value of r is::0
In the above example, when the value "x" is divided by "0" an exception is thrown. Using the "catch" statement the exception is caught. This is the Error Handler System in C++.